Remote file sharing based on content filtering

ABSTRACT

Embodiments of the invention include a system, method and computer program product for accessing a remote file system in which files in the remote file system are mapped to a local file system that is coupled to the remote file system by a network, wherein the mapped files meet a filtering criterion and are used in subsequent file operations at the local file system.

BACKGROUND

Embodiments of the invention relate generally to computer file systems,and more particularly to accessing files in another computer systembased on content filtering.

Computers are commonly interconnected in a network for usercommunications, exchanging data, or retrieving data as in aclient-server configuration. In a networked computing environment, auser may need to access data files stored on another computer that isconnected to the user's computer by a network in an operation calledfile sharing. The files may be in a shared file system operating at theremote computer. There are various commonly used file systems such asDistributed File System (DFS) and Global Storage Architecture (GSA). Inorder to access the shared files, the user often initiates a processreferred to as drive mapping which associates the remote file structurewith an unused local drive designation at the user's local computer. Theuser and applications running on local computer can then perform fileoperations on the mapped remote files as if the files reside in a datastorage drive at the local computer.

In Windows™ operating systems that commonly operate on personalcomputers, a user may initiate the drive mapping using system optionssuch as “Map Network Drive”, a command “net use”, or the like. (Windowsis a trademark of Microsoft Corporation in the United States, othercountries, or both.) In Unix® type operating systems, a drive mappingmay be set up with the command “mount” or the like. (UNIX is aregistered trademark of The Open Group in the United States and othercountries.) File operations on the mapped drive, however, can be slow,especially when network bandwidth is limited and the shared file systemcontains a large number of folders and files. For example, a file search(e.g. Google desktop search) must iterate all the files and essentiallyread all the data from the files in the mapped drive that are sent tothe client machine through the network. The file search operation isthen performed on the returned files in the local disk to find the filesthat match the search expression.

BRIEF SUMMARY

Embodiments of the invention include a system, method and computerprogram product for accessing a remote file system in which files in theremote file system are mapped to a local file system that is coupled tothe remote file system by a network, wherein the mapped files meet afiltering criterion and are used in subsequent file operations at thelocal file system.

The details of the embodiments, both as to their structure andoperation, are described below in the Detailed Description section inreference to the accompanying drawings. The Brief Summary is intended toidentify key features of the claimed subject matter, but it is notintended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a computing environment supporting file sharing inwhich aspects of the invention may be implemented, according to anexemplary embodiment.

FIG. 2 illustrates a block diagram of a computer system that may be usedfor file sharing and providing aspects of the invention, according to anexemplary embodiment.

FIG. 3 illustrates an example of a file tree structure having files andfolders that may be drive mapped, according to an embodiment of theinvention.

FIG. 4 illustrates an example of a file sharing operation in which afile structure on a remote computer is mapped to a local drive.

FIG. 5 illustrates a block diagram of drive mappings between a localcomputer system and multiple remote file sharing systems according to anexemplary embodiment.

FIG. 6 illustrates an exemplary drive mapping configuration thatsupports cached filtering and incremental filtering of the files andfolders in a remote file system, according to an embodiment of theinvention.

FIG. 7 illustrates an exemplary user interface for specifying a remotefile structure to be mapped for file sharing, according to an embodimentof the invention.

FIG. 8 illustrates an exemplary user interface for specifying afiltering criterion to be applied to target files and folders in aremote file system, according an embodiment of the invention.

FIG. 9 illustrates an example of a content-filtered drive mappingaccording an embodiment of the invention.

FIG. 10 is a flow chart of a process for mapping a remote file structureto a local drive based on content filtering, according to an exemplaryembodiment of the invention.

FIG. 11 is a flow chart illustrating a process for filtering files andfolders in a remote file system with a filter cache, according to anexemplary embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the invention relate to accessing a remote file system bymapping files in the remote file system to a local drive wherein themapped files meet certain filtering criteria and performing subsequentfile operations on the mapped files.

Referring now to the drawings and in particular to FIG. 1, there isillustrated an example of a computing environment in which aspects ofthe invention may be implemented. The computing configuration in FIG. 1is presented only by way of example and is not intended to be limiting.The file access systems and methods disclosed herein may be applicableto a wide variety of different computers, servers, storage systems, andnetwork architectures, in addition to the configuration in FIG. 1. Theillustrated configuration may comprise multiple computers 10-12 that areinterconnected by a computer network 13. The computer network 13 may bea wide area network (WAN), a local area network (LAN), a privateintranet, or the Internet. The computers 10-12 may include a server 12that executes various programs and provides a variety of computingfunctions to client computers 10-11. Remote computers 11-12 may havedata files in their file systems that local computer 10 may need toaccess. A file system may maintain the data files in a data storagesystem that is attached to a server computer 12 by a storage network orsimilar means.

FIG. 2 is a block diagram of a computer system that may be used in thecomputing environment of FIG. 1 for providing aspects of the invention.Data processing system 210 includes a processor unit 211, a memory unit212, a persistent storage 213, a communications unit 214, aninput/output unit 215, a display 216 and a system bus 217. Computerprograms are typically stored in persistent storage 213 until they areneeded for execution by an operating system (not shown) running inmemory unit 212. At that time, the programs are brought into the memoryunit 212 so that they can be directly accessed by the processor unit211. The processor unit 211 selects a part of memory unit 212 to readand/or write by using an address that the processor 211 gives to memory212 along with a request to read and/or write. Usually, the reading andinterpretation of an encoded instruction at an address causes theprocessor 211 to fetch a subsequent instruction, either at a subsequentaddress or some other address. The processor unit 211, memory unit 212,persistent storage 213, communications unit 214, input/output unit 215,and display 2116 interface with each other through the system bus 217.

File Systems

File systems allow users and application programs to access data storedon storage devices in a logical way without being concerned with howdata is actually stored on the storage devices. The data units that thestorage devices use to store data may vary depending on the device typeand data format of the device, e.g., disks, tapes, solid state memories,etc. Application programs may request data in units of bytes, dataentities, or data files. The file systems then map the program addressspaces to the storage device address spaces and access data stored inthe storage spaces at the device data addresses.

Data on storage devices may be organized as volumes, directories orfolders, depending on file structures and naming conventions supportedby the operating systems. Volumes, directories and folders may furtherhave data files. For example, a folder may include other lower-levelfolders. File systems may present files to application programs throughdirectory files that form a tree-like hierarchy of files and directoriesthat contain more files. File names are unique to directories but not tofile folders or volumes. FIG. 3 illustrates an example of a file treestructure 300 that includes multiple file folders 301. Each folder 301may have additional folders 302 and files 303. Although exemplaryembodiments of the invention are described using file systems havingfiles and folders, the embodiments are applicable to other forms of filesystems and not limited to just file systems that include files andfolders. In addition to traditional file systems, the embodiments may beapplicable to other forms of data collections such as removable filesystems, abstracted file systems, RAM disks, databases, and other dataorganizations.

A traditional file sharing system is based on user permission or roles.As long as the user has access permission to a file system, all thefiles and folders in the file system that the user has permission toaccess may be mapped to a user local drive and available to the user. Insuch as system, access to files or folders is granted to certain rolesor groups, and all the users in the same role or group have the sameaccess rights. For instance, if a file system has ten folders, a“Viewers” role or group may be granted “read” permission to five of theten folders. Subsequently, when a user in the “Viewers” group maps filesin the file sharing system, these five folders are available to bemapped to the user's local system.

The above type of file sharing may impact system performance andresponse time as the file sharing system may send all the availablefiles and folders to a user regardless of whether the files and foldersrelate to what the user is interested in. Embodiments of the inventionimprove file sharing performance through content filtering during anetwork drive mapping. Only the file folders and files in a network filesystem that meet certain user filtering criteria, and thus may be of theuser's interest, are mapped to the user's local drive.

In the above “Viewers” group example, a content filter may further limitthe available folders to two folders that are of interest to the user,rather than original five file folders. Such as content filteringimproves overall performance as it results in a smaller number of filesbeing transferred to the user across the network. Subsequent fileoperations may be performed only on the filtered set of two file foldersrather than on all the five file folders which the user has permissionto access in the remote file system.

FIG. 4 illustrates an example of a drive mapping in which a filestructure 400 on a remote computer 401 is mapped to a drive on a localcomputer 402. In this example, a local computer 402 may have fourstorage drives A, B, C and D, where drive D (406) is a mapped driveassociated with the remote file structure 400. As an example, the filestructure 400 includes files 412 and folders 411 in the “Images” folder410, which is on drive Q (408) of the remote computer 401. In additionto drive Q (408), the remote computer 401 may have drives P (407) anddrive R (409) which are not involved in the drive mapping.

Once the operating system (not shown) of the local computer 402 hasmapped the remote file structure 400 to the local drive D (406), usersand application programs of the local computer 402 may access folders411 and files 412 in the remote file structure 400 as if they currentlyreside on the local drive D (406). In a drive mapping operation, thefolders 411 and files 412 still remain in the file structure 400 at theremote computer 401 and are only sent to the local computer 402 when theuser or a program at the local computer 402 accesses them.

A user may initiate the file sharing illustrated in FIG. 4 using a “netuse” command (or similar commands) in a Windows™ based computer systemor a “mount” command (or similar commands) in a Unix® based computersystem. The user may perform the drive map operation through commandline or through a graphical user interface (GUI). For instance, to map adrive in Windows™, the user may issue a command “net use z:\\blah\sharename”. To mount a file system in a Unix® system, the usermay issue a command “mount blah.com:/share/misc/local”.

FIG. 5 illustrates a block diagram of a file sharing environmentcomprising a local computer and multiple remote file systems, accordingto an exemplary embodiment. As an example, user 501 may be using a localcomputer 502 to access multiple file systems 509-510 that respectivelyoperate in remote computers 507-508. In order to access the file systems509-510, the user 501 may need to log into the remote computers 507-508and be authorized by the respective file sharing authorizing components513-514. The login may involve providing appropriate user securitycredentials to the remote computers 507-508, which may comprise user IDand password pairs.

File sharing authorizing components 513-514 are security features in theoperating systems of the remote computers 507-508 that examine theuser's credentials to determine whether to grant the user access tocertain files or folders in the respective file systems 509-510. Forexample, the file sharing authorizing component 513 may determine thatthe user 501 has “read” access to five shared folders 515 of the tenfolders 511 in the file sharing system 509. Subsequently, only thesefive folders 515 may be allowed to map to the user's local computer 502,and the user may decide to map any one, two, or all of the five folders515, or a subfolder of any allowed folders 515 to the user's localsystem. A file sharing authorizing component 513-514 may be acombination of file sharing permission and login credentialauthorization. In addition, the file sharing permission components513-514 may decide the level of file access that the user would have fora particular file or folder, such as the user's authority to read,write, or update a file or a folder.

In the above example, any user change to a mapped file in the user'slocal system cannot be propagated to the file sharing system because ofthe “read only” permission. The file sharing authorizing components513-514 may determine whether a logged-in user has the file accessprivileges that user has requested. In the example, if the user requeststo map a file that is not in any of the five folders that the user hasread permission, then the remote file sharing system would deny therequest. The file sharing permission is generally configured when filesand folders are shared. For example, in a Windows™ operating system, auser may right-click a directory under the “Windows Explorer” menu, then“Sharing and Security”, and select the “Security” tab to set up filesharing permission.

Once authorized to access the file systems 509-510, the user 501 mayspecify one or more filtering criteria 517-518 for each of therespective file sharing systems 509-510. The user 501 may configure thefiltering criteria 517-518 at the local computer 502 to be respectivelyapplied at the remote file systems 509-510. The filters 517-518 may bein the form of regular expressions. A regular expression is a patternthat describes how the matching should be done and contains desiredcriteria such as uppercase or lowercase, character ranges, and characterpositions. An example of a regular expression is: ^[A-Za-z_]*$, whichindicates a match on the English letters, underscores, and spaces.Another example of a regular expression is[0-9]{3}\-?[0-9]{2}\-?[0-9]{4}, which indicates a match on a US socialsecurity number in the forms of 123-45-6789 and 123456789.

The filters 517-518 may be in other forms of expressions that are agreedupon between user and the shared file systems. For instance, the usermay use the filter expression “after01102010” to specify that only thefiles created or updated after Jan. 10, 2010 are to be mapped. Thefilters 517-518 may be a combination of the two expressions above. Forexample, the user may specify the filter “name: ^[A-Za-z_]*$, metadata:after01102010” to indicate that only files created or updated after Jan.10, 2010, and whose names contain English letters, underscores, andspaces are to be mapped.

Further, the filters 517-518 may be configured to apply to folder andfile names, file contents or both. The remote file sharing systems509-510 respectively apply the filtering criteria 517-518 to filesystems 509-510 and only return the files or file folders 505-506 in thefile systems 509-510 that satisfy the filtering criteria 517-518 to bemapped to a local drive in the user's computer 502. In the aboveexample, after the content filter 517 is applied, only two file folders505 of the five folders 515 that the user has “read” permission in thefile sharing system 516 would be mapped to the user's local computer502.

The filtering criteria 517-518 may apply to the names and contents offiles and folders, as well as file attributes and metadata such as fileowner information, file access rights, file mode, file creation date,file update times and dates, revision information, attributes relatingto operation systems, and other file metadata. The following examplesillustrate some content filtering criteria 517-518 that may be used inan embodiment of the invention.

-   -   Metadata filter: after 01-10-2010    -   Name filter: ^[A-Z a-z_]*$    -   Content filter: [0-9]{3}\-?[0-9]{2}\-?[0-9]{4}

The metadata filter allows files that are created or updated after Jan.10, 2010 to be mapped to a local file structure. The name filter allowsfile and directory names that contain only English letters, underscores,and spaces to be mapped to a local file structure. The content filterallows only the files that contain a US social security number in theform of 123-45-6789 and 123456789 to be mapped to the local filestructure.

FIG. 6 illustrates another embodiment of a file sharing system that usesa content filter cache to further improve file sharing response time.The embodiment in FIG. 6 further illustrates a caching of the filteringcriteria and filtered files and folders for better system performance.In order to access files 605 in a remote file system 604, a user 601 mayprovide login credentials 602 to the remote computer (not shown) thathosts the remote file system 604. The credentials may be supplied whenthe user 601 initiates an operation to map the remote file system 604 toa local drive.

The user 601 may further specify a set of filtering criteria 603 asdescribed above with reference to FIG. 5 to be applied to the sharedfiles and folders. File sharing authorization component 606, which maybe part of the file sharing system 604 or the remote computer hostingthe file system 604, may grant user 601 access to the files and folders605 based on the login credentials 602. The user 601 may then accessshared files 607 along with other file users who are authorized by theremote computer to access the shared files 607.

In the illustrated embodiment, the remote file sharing system 604 mayfurther apply filtering criteria 603 to the shared files and folders 607and identify only those that satisfy the filtering criteria 603. Thefiltered files and folders are sent to the user 601 as filtered filesand folders 610, which are mapped to a local drive in the user'scomputer. The filtering criteria 603 and references to the resultingfile names of the matched files and folders, such as directory paths tothe files and folders, may be stored in a cache memory 609 of the remotefile sharing system or a network component connecting the local andremote computers. The remote file sharing system may use the cachedfiltering criteria and cached file-filtering results for future drivemap requests from the same user or other users to improve file sharingperformance.

For any new drive map request with a filtering criterion, if thecriterion in the request exists in the cache 609, then the mapped filesin the cache 609 that relate to the criterion may be returned to theuser. If the criterion in the request is a combination of two or morecriteria in the cache 609, then the combined files for these two or morefile criteria in the cache 609 may be returned to the user. If thecriterion in the request is a super set of a criterion or criterioncombination in the cache 609, then a differential criterion may be usedto search remote file system 604 to find the corresponding files, andthe differential criterion and the files found may be cached, and thecombined file system results from the cache 609 and from the search maybe returned.

For example, if a user's request specifies a content filter:^[A-Za-z_]*$ for identifying the English alphabets, underscores, andspaces in a file name, then the remote file sharing system may examinethe cache 609 to identify the files whose file names contain the Englishcapital letters, underscores, and spaces in their file names. The sharedfile system may further determine that the filter criterion ^[A-Za-z_]*$in the request is a super set of a previous filter criterion ^[A-Z_]*$in the cache 609. In that case, the remote file sharing system may tosearch the remote file system 604 for relevant files and folders using adifferential filter criterion ^[a-z_]*$. The files and folders resultingfrom the filtering using the differential filter criterion ^[a-z_]*$ maybe combined with previous results in the cache 609 for the filter^[A-Z_]*$ and returned to the user. The differential criterion ^[a-z_]*$and the files and folders resulting from the filtering using thiscriterion may further be cached to respond to future content filteringrequests.

The content filter cache just described may improve the file sharingperformance considerably as the amount of time needed for matching thefiles and folders against the filter criteria is greatly reduced.

The exemplary file sharing system illustrated in FIG. 6 may furthercomprise an incremental filtering component 608 for updating the contentfilter cache and minimizing the amount of data in the remote filesharing system 604 to be filtered during file mapping and thus furtherimproving system performance. As contents in the remote file sharingsystem 604 change, such as file data, file names, and file structuremetadata, the filtered files 610 and cached information in the filtercache 609 may become obsolete. The incremental filtering component 608may perform a partial filtering by applying the filtering criteria 603only against the files, folders, or and organization metadata in theremote file system 604 that have changed since the last filtering,rather than against the entire file system.

An incremental filtering may be performed whenever a file change isdetected or periodically at certain time intervals to update theaffected cache entries in the remote file sharing system, independent ofmapping requests. Thus, this incremental filtering may significantlyreduce the amount of data to be filtered at the remote file systemduring subsequent file mapping requests and further improve file sharingperformance.

A user may initiate a drive map with file filtering criteria though auser interface provided at the local computer. FIG. 7 illustrates anexample of a drive map user menu. Drive map user menu 701 may comprise a“Networked Computer” field 702 for the name of the remote computerhosting the files that the user is interested in, and a “Drive To Map”field for the remote drive to be mapped. The user menu 701 may furtherinclude a “Local Drive” field 703 for the user to enter a local driveidentifier for the mapped drive.

FIG. 8 illustrates a user menu on which the user may specify thecriteria to be used for filtering contents of a remote file structure ina drive map. The filter user menu 801 may include a “Filter” field 801for entering the file filtering criteria, and an “Applied To” field 802for specifying file structures, metadata, contents, folders, or filesthat the criteria are to be applied to. In the “Filter” field 801, theuser may specify a regular expression or other expressions to be appliedagainst the remote files. For example, a filter of ^[A-Za-z_]*$ may beused for mapping only the files with the file names containing Englishalphabets, spaces and underscores. In the “Applied To” field 802, theuser may enter the type of data to be filtered, such as file name,folder name, directory name, file contents, file update information, andother metadata on the remote file system.

A user may specify a filter criterion through a command. A component inthe user's local computer may provide a new command or modify anexisting command to accept a content filter optional parameter. Forexample, in Windows™ systems, the user may issue the command “net use z:\\blah\sharename-filter “^[A-Za-z_]*$””. In Unix® and Linux® systems,the user may issue the command “mount blah.com:/share/misc/local-filter“^[A-Za-z_]*$”)”. (Linux is a registered trademark of Linus Torvalds inthe United States, other countries, or both.)

FIG. 9 illustrates an example of a content-filter drive mappingaccording to an embodiment of the invention. File structure 901comprises files and folders in a remote file system that have namescontaining both letters and numbers. In a drive map operation, the usermay be interested only in the files and folders that include letters intheir names, but not numbers. By applying the user's filtering criteriaof ^[A-Za-z_]*$ to the file and folder names in file structure 901, theremote computer returns the set of filtered files and folders in mappeddrive Y (902).

FIG. 10 is a flow chart of a process for mapping a remote file structureto a local drive based on content filtering in accordance with anexemplary embodiment. The sequence of operations as shown is just oneexample and not intended to be limiting on the order of the operationsthat may be implemented. The process starts with the user initiating adrive mapping at step 101. Through a filtering user interface such asthe user interface illustrated in FIG. 8, the user may specify desiredcontent filtering criteria at step 102. The remote file sharing systemmay examine user credentials, per step 103, to determine whether theuser has the required credentials to access the remote file system. Ifthe user has access rights to the file system, then the remote filesharing system may grant the user file sharing privileges for therequested mapping, per step 104. With the authorized file sharing, theuser may access all files and folders in the requested mapping directoryof the remote file system, if desired.

At step 105, the remote file sharing system applies user-specifiedfiltering criteria to the shared files and folders to identify thosethat meet the criteria. The remote file sharing system then returns theidentified files and folders to the user in step 106. The user may thenperform file operations on the returned files and folders such asopening, copying, and editing the files at the local computer, at step107.

In order to reduce the amount of data to be filtered, the remote filesharing system may identify the files, folders, their contents, or filesystem metadata that have changed since the last filtering, at step 108.The filtering criteria and results of the last filtering operation maybe in the cache 609 as described above with reference to FIG. 6. Theremote file sharing system may perform an incremental filtering on thechanged contents in the file system, per step 109, to update the contentfilter cache. At a later time, the same user or another user may desireto map the same remote file structure again. The remote file sharingsystem may return the filtered files and folders to the user. Such acontent filter, content filter cache and incremental filtering togetherimprove system performance as they reduce the amount of remote file datato be filtered and transmitted across the network connecting the localand remote computers.

FIG. 11 illustrates a flow chart of an exemplary process forincrementally filtering files and folders of a remote file sharingsystem based on a set of user criteria, according to an embodiment ofthe invention. The process begins at step 111 with the user initiating afile sharing request that includes a filter to be applied against thefiles and folders of the remote file sharing system. The remote filesharing system may examine the cache 609 to determine whether therequested filter and filtered results may be in the cache 609, at step112. If the user's requested filter and filtering results are in thecache 609, then the remote file sharing system returns the files andfolders currently in the cache 609 that have been identified in aprevious filtering using the same cached filter, at step 115. If therequested filtering is not in the cache 609, then the remote filesharing system applies the requested filter criteria against the remotefile structure to identify files and folders that match the filter, atstep 113. The remote file sharing system may store the matching filesand folders in the cache 609, at step 114, and return the matching filesand folders to the user, at step 115.

The subject matter described above is provided by way of illustrationonly and should not be construed as limiting. Various modifications andsubstitutions of the described components and operations can be made bythose skilled in the art without departing from the spirit and scope ofthe invention defined in the following claims, the scope of which is tobe accorded the broadest interpretation so as to encompass suchmodifications and equivalent structures. The systems, methods, andprocedures described herein can be embodied in a programmable computer,computer executable software, or digital circuitry. The software can bestored on computer readable media. For example, computer readable mediacan include a floppy disk, RAM, ROM, hard disk, removable media, flashmemory, a “memory stick”, optical media, magneto-optical media, CD-ROM,etc.

As will be appreciated by one skilled in the art, aspects of theinvention may be embodied as a method, system or computer programproduct. Accordingly, aspects of the invention may take the form of anentirely hardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Furthermore,aspects of the invention may take the form of a computer program productembodied in one or more computer readable medium(s) having computerreadable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Morespecific examples (a non-exhaustive list) of the computer readablestorage medium would include the following: an electrical connectionhaving one or more wires, a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,a portable compact disc read-only memory (CD-ROM), an optical storagedevice, a magnetic storage device, or any suitable combination of theforegoing. In the context of this document, a computer readable storagemedium may be any tangible medium that can contain, or store a programfor use by or in connection with an instruction execution system,apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, etc., or any suitable combination ofthe foregoing.

Computer program code for carrying out operations for aspects of theinvention may be written in any combination of one or more programminglanguages, including an object oriented programming language such asJava, Smalltalk, C++ or the like and conventional procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The program code may execute entirely on the user's computer,partly on the user's computer, as a stand-alone software package, partlyon the user's computer and partly on a remote computer or entirely onthe remote computer or server. In the latter scenario, the remotecomputer may be connected to the user's computer through any type ofnetwork, including a local area network (LAN), a wide area network(WAN), or the connection may be made to an external computer, forexample, through the Internet using an Internet Service Provider.

Aspects of the invention are described above with reference to flowchartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products according to embodiments of the invention. Itwill be understood that each block of the flowchart illustrations and/orblock diagrams, and combinations of blocks in the flowchartillustrations and/or block diagrams, can be implemented by computerprogram instructions. These computer program instructions may beprovided to a processor of a general purpose computer, special purposecomputer, or other programmable data processing apparatus to produce amachine, such that the instructions, which execute via the processor ofthe computer or other programmable data processing apparatus, createmeans for implementing the functions/acts specified in the flowchartand/or block diagram block or blocks.

These computer program instructions may also be stored in a computerreadable medium that can direct a computer, other programmable dataprocessing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablemedium produce an article of manufacture including instructions whichimplement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The flowchart and block diagrams in the figures described aboveillustrate the architecture, functionality, and operation of possibleimplementations of systems, methods and computer program productsaccording to various embodiments of the invention. In this regard, eachblock in the flowchart or block diagrams may represent a module,segment, or portion of code, which comprises one or more executableinstructions for implementing the specified logical function(s). Itshould also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in thefigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. It will also be noted that each block of the block diagramsand/or flowchart illustration, and combinations of blocks in the blockdiagrams and/or flowchart illustration, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware and computerinstructions.

What is claimed is:
 1. A system comprising: a remote file structureresiding on a remote drive storing a plurality of files; a local filestructure operating at a local computer coupled to the remote filestructure by a network, wherein the local file structure resides at alocal drive; a file sharing authorizer for receiving user credentials; auser interface, at the local computer, for specifying a user-specifiedfiltering criterion to access the files of the remote file structure asshared files; and a logic component configured to only map the files inthe remote drive to the local drive that meet the user-specifiedcriterion in a form of a regular expression, wherein the mapping isbased on the user credentials, wherein the mapped files meet theuser-specified filtering criterion and are used for subsequent fileoperations at the local file structure, wherein the user-specifiedfiltering criterion comprises at least one user filter for selectingfiles of the remote drive as the shared files of said mapping of thedrives, and wherein the regular expression is a pattern that describeshow matching is to be performed and comprises a character range and acharacter position.
 2. The system of claim 1, further comprising: alogic component for configuring the user-specified filtering criterionat the local computer; and a logic component configured to apply thefiltering criterion to the remote file structure.
 3. The system of claim1, further comprising a cache coupled to the network for storing theuser-specified filtering criterion for the drive mapping and informationon the mapped files of the remote drive to the local drive.
 4. Thesystem of claim 1, further comprising an incremental filtering componentto map the files in the remote drive that have changed since the lastmapping based on the filtering criterion applied to the drive mapping.5. The system of claim 1, wherein the local drive is a logical drive inthe local computer.
 6. The system of claim 1, wherein the remote filestructure is a shared file structure.
 7. The system of claim 1, whereinthe user-specified filtering criterion relates to file contents and filemetadata.
 8. A computer program product for accessing a remote filesystem comprising a computer readable non-transitory storage mediumhaving computer readable program code embodied therewith, the computerreadable program code comprising computer readable program codeconfigured to: receive user credentials; provide a user interface forspecifying a user-specified filtering criterion at a local computer tomap a remote drive storing the files of the remote file system to alocal drive, as shared files; authorize user access to the remote filesystem based on the user credentials; and only map files in the remotedrive to the local drive operating at the local computer that meet theuser-specified filtering criterion in a form of a regular expression,wherein the local computer is coupled to the remote file system by anetwork, wherein the mapped files meet the user-specified filteringcriterion and are used in subsequent file operations at the local filesystem, wherein the user-specified filtering criterion comprises atleast one user filter for selecting files of the remote drive, as theshared files of said mapping of the drives, and wherein the regularexpression is a pattern that describes how matching is to be performedand comprises a character range and a character position.
 9. Thecomputer program product of claim 8, further comprising computerreadable program code configured to store the user-specified filteringcriterion and information on the mapped files in a cache coupled to thenetwork.
 10. The computer program product of claim 9, further comprisingcomputer readable program code configured to incrementally update thecache based on changes in the remote file system.
 11. The computerprogram product of claim 8, wherein the files are remapped to the localdrive in response to a change in the user-specified filtering criterion.12. The computer program product of claim 8, wherein the user-specifiedfiltering criterion relates to file contents and file metadata.
 13. Acomputer implemented method for accessing a remote file system,comprising: receiving user credentials; providing a user interface forspecifying a user-specified filtering criterion at a local computer tomap a remote drive storing the files of the remote file system to alocal drive, as shared files; authorizing user access to the remote filesystem based on the user credentials; and only mapping the files in theremote drive to a local drive operating at the local computer that meetthe user-specified criterion in an form of a regular expression, whereinthe local computer is coupled to the remote file system by a network,wherein the mapped files meet the filtering criterion and are used insubsequent file operations at the local file system, wherein theuser-specified filtering criterion comprises at least one user filterfor selecting files of the remote drive, as the shared files of saidmapping of the drives, and wherein the regular expression is a patternthat describes how matching is to be performed and comprises a characterrange and a character position.
 14. The method of claim 13, wherein theuser-specified filtering criterion is configured at the local computerand applied at the remote file system.
 15. The method of claim 13,wherein the user-specified filtering criterion and information on themapped files are stored in a cache coupled to the network.
 16. Themethod of claim 15, wherein the cache is incrementally updated based onchanges in the remote file system.
 17. The method of claim 13, whereinthe files are remapped to the local drive in response to a change in theuser-specified filtering criterion for the drive mapping.
 18. The methodof claim 13, wherein the user-specified filtering criterion relates tofile contents and file metadata and wherein the user-specified filteringcriterion comprises a field identifying at least one folder stored onthe remote drive to which the user-specified filtering criterion is tobe applied.
 19. The system of claim 1, wherein the user-specifiedfiltering criterion specifies type of data to be filtered during themapping of the files stored on the remote drive to the local drive. 20.The system of claim 4, wherein the incremental filtering component onlyupdates the files in the remote drive that have changed and whereinincremental filtering by the incremental filtering component isindependent of the drive mapping.
 21. The system of claim 1, wherein theuser interface comprises: at least one field for a user inputtinginformation about the local drive to map to in the local computer andfor a user inputting information about the remote drive in a remotecomputer which is to be mapped to the local drive, at least one fieldfor a user specifying a filter from the at least one filter forselecting files of the remote drive as the shared files of said mappingof the drives, wherein the filter is applied to at least one ofdirectories present on the remote drive such that only files compliantwith the filter are mapped to the local drive, and wherein the localdrive stores a shared directory comprising only a portion of the filesstored in the directory of the remote drive.
 22. The system of claim 1,wherein the user-specified filtering criterion comprises at least one ofa date and alphanumeric characters that are to be applied to file namesof the plurality of files stored at least in a portion of the remotedrive and wherein the user-specified filtering criterion is applied tothe plurality of files and at least two files are displayed at the localfile structure.